CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
ASSETS
Cash and cash equivalents	$ 63,312	$ 60,330
Accounts receivable, less allowance for doubtful accounts of $1,912 and $1,581	331,760	326,087
Expenditures billable to clients	69,863	58,842
Other current assets	22,629	16,892
Total Current Assets	487,564	462,151
Fixed assets, at cost, less accumulated depreciation of $124,884 and $115,792	51,942	52,914
Investment in non-consolidated affiliates	196	0
Goodwill	711,336	720,071
Other intangibles assets, net	50,809	63,243
Deferred tax asset	18,775	9,332
Other assets	45,065	37,234
Total Assets	1,365,687	1,344,945
LIABILITIES, REDEEMABLE NONCONTROLLING INTERESTS, AND DEFICIT
Accounts payable	213,016	356,847
Accruals and other liabilities	286,101	93,895
Advance billings	154,886	131,908
Current portion of long-term debt	784	1,858
Current portion of deferred acquisition consideration	43,872	104,325
Total Current Liabilities	698,659	688,833
Long-term debt	550,489	429,845
Long-term portion of deferred acquisition consideration	58,882	92,121
Other liabilities	44,024	47,985
Deferred tax liabilities	53,730	53,018
Total Liabilities	1,405,784	1,311,802
Redeemable Noncontrolling Interests (Note 2)	138,623	117,953
Commitments, contingencies and guarantees (Note 11)
Shareholders' Deficit:
Preferred shares, unlimited authorized, none issued	0	0
Shares to be issued, 28,000 shares	424	424
Charges in excess of capital	(96,553)	(72,913)
Accumulated deficit	(371,255)	(316,713)
Stock subscription receivable	(55)	(55)
Accumulated other comprehensive loss	(8,296)	(7,445)
MDC Partners Inc. Shareholders’ Deficit	(220,723)	(142,832)
Noncontrolling Interests	42,003	58,022
Total Deficit	(178,720)	(84,810)
Total Liabilities, Redeemable Noncontrolling Interests and Deficit	1,365,687	1,344,945
Common Class A [Member]
Shareholders' Deficit:
Common Stock	255,011	253,869
Common Class B [Member]
Shareholders' Deficit:
Common Stock	$ 1	$ 1